Conventionally, a traveling cellulosic web has been heated by flooding the web with a liquid, whereby uncontrollable penetration of the liquid into the web occurs. As this overflow-flooding step of heating takes place in an open space, it is hampered by problems from the overflow of the liquid and release of expansion steams.
It is an object of the present invention to overcome the above-mentioned problems by virtue of a method characterized in that said closed space is defined by two wires and side deckles, and that said liquid is applied through the wires into the web both from below the bottom wire and from above the top wire.